1. Field of the Invention
The present invention relates to an inexpensive refueling machine having high safety.
2. Description of the Related Art
Electric equipment such as a pump, a motor, a flowmeter, an indicator and a control circuit is built in a refueling machine conventionally used at a gas station for such a fuel as gasoline and light oil. The electric equipment is used in an explosive atmosphere. As a result, such electric equipment must be structured to be explosion-proof, causing the cost of a refueling machine to go up. Further, since the electric equipment is disposed in an explosive atmosphere although being resistant against explosion, it is impossible to completely avoid the danger of explosion and there has been a need for improvement for further enhancing the safety of a gas station.
Such a proposal has been made by, for example, Japanese Patent Laid-open No. 60-172700 that some equipment of a refueling machine is disposed at an inexplosive place, paying attention to an island provided in a gas station for the purpose of making automobiles come in and go out of the gas station, thereby avoiding such equipment of the refueling machine from being structured to be explosion-resistant. FIG. 1 schematically shows a cross section of a refueling machine disclosed in the above Official Gazette. An island I is provided in site D of a gas station, and a first motor M1, a first pump P1, a second motor M2 and a second pump P2 provided in correspondence with the kind of fuels are contained within the Island I. A first casing 1 supported by a pole 3 on the island I and containing first and second refueling amount indicators 4a, 4b in an airtight manner is provided at an inexplosive place. Consequently, the electric equipment contained within the first case 1 does not have to have an explosion-proof structure. Electric wires 5 extending from those refueling amount indicators pass through the island I and are then connected to pulse transmitters 6a, 6b within a second casing 2.
Within the second casing are provided flowmeters 7a, 7b respectively connected to the pulse transmitters 6a, 6b. Pipes L1, L2 extending from the pumps P1, P2 are connected through flowmeters 7a, 7b to refueling nozzles 8a, 8b, respectively.
As such, the refueling machine disclosed in Japanese Patent Laid-open No. 60-172700 is structured in such a manner that the first casing 1 provided outside of an inexplosive place is connected through pipes L1, L2 and wires 5 to the second casing 2 provided in an explosive place. Since such electric equipment as the pulse transmitters 6a, 6b is contained in the second casing 2 provided in an explosive place and the motors M1, M2 and the pumps P1, P2 are provided in the island I, the electric equipment contained in the second casing 2 and the island I must be structured to be explosion-resistant. consequently, the proposal described above has a limit to a cost reduction of a refueling machine and does not substantially enhance the safety of a refueling machine.